CN104600194B

CN104600194B - Improve magnetic film AMR metal Ta film build methods

Info

Publication number: CN104600194B
Application number: CN201410856751.3A
Authority: CN
Inventors: 刘善善
Original assignee: Shanghai Huahong Grace Semiconductor Manufacturing Corp
Current assignee: Shanghai Huahong Grace Semiconductor Manufacturing Corp
Priority date: 2014-12-29
Filing date: 2014-12-29
Publication date: 2017-08-08
Anticipated expiration: 2034-12-29
Also published as: CN104600194A

Abstract

The invention discloses a kind of metal Ta film build methods for improving magnetic film AMR, including step：Step one, substrate is handled using etching technics；Step 2, row metal Ta film forming is entered in the substrate surface, forms Ta films；Step 3, Ni is carried out on the Ta films surface₈₁Fe₁₉The film forming of film and nitridation tantalum film；Step 4, to the Ta films, Ni₈₁Fe₁₉Film and nitridation tantalum film are made annealing treatment, so as to form anisotropic magnetoresistance film.The present invention can be reduced effectively because high power sputters the crystal defect caused using the Ta cushions of variable-current mode film forming formation, and effectively improves Ni₈₁Fe₁₉The amr effect of film.

Description

Improve magnetic film AMR metal Ta film build methods

Technical field

It is more particularly to a kind of to improve magnetic film AMR (anisotropy the present invention relates to a kind of semiconductor integrated circuit field Magneto-resistor) metal Ta film build methods.

Background technology

Anisotropic-magnetoresistance effect is used for tape recording system at first, is then applied to disk recording system, magnetic Disk read-out system and the sensor for detecting low-intensity magnetic field, due to having great advantage in volume, quality and cost, therefore, even if After giant magnetoresistance effect discovery, the computer read head and sensor made of traditional anisotropic magnetoresistance film is in market On still account for very big proportion.In order that device miniaturization, perm (NIFE) alloy firm for read head must be made very thin, coercive Power very little, and be worth as big as possible.

Below curie point, metallic ferromagnetic resistivity is different with the relative orientation of electric current I and magnetization M, is referred to as Anisotropic-magnetoresistance effect, i.e. ρ_∥(I∥M)≠ρ_⊥(I⊥M)。

Anisotropic magnetoresistance (AMR) ratio is normally defined：

AMR=Δs ρ/ρ=(ρ-ρ_⊥)/ρ₀

Wherein, ρ here₀For resistivity of the ferromagnetic material under preferable demagnetized state.But due to the shape that preferably demagnetizes State is difficult to realize, usual ρ₀It is approximately equal to average resistivity ρ av, i.e. ρ₀≈ ρ av=ρ_∥+ρ_⊥。

Said from using angle, during as sensor, big sensitivity is on the one hand needed, while being also required to high signal to noise ratio. In order to improve signal to noise ratio, as a result show, the signal to noise ratio of the material of interface crystal lattice uniformity difference is big, also easy in heat treatment process Produce the defect of distortion of lattice or nanometer scale.

Considered based on background above, the crystal lattice difference improved between AMR values and film bed boundary is big, could cause film forming Perm (NIFE) alloy firm magnetic effect it is stronger.

The content of the invention

The technical problem to be solved in the present invention is to provide a kind of metal Ta film build methods for improving magnetic film AMR.Using this The method of invention can effectively improve NiFe films (i.e. Ni₈₁Fe₁₉Film) amr effect.

In order to solve the above technical problems, the metal Ta film build methods for improving magnetic film AMR of the present invention, including step：

Step one, substrate is handled and (pre-processed) using etching technics；

Step 2, row metal Ta film forming is entered in the substrate surface, forms Ta films (Ta films can be used as cushion)；

Step 3, Ni is carried out on the Ta films surface₈₁Fe₁₉The film forming of film and nitridation tantalum film；

Step 4, to the Ta films, Ni₈₁Fe₁₉Film and nitridation tantalum film are made annealing treatment, so as to form anisotropic magnetic Resistive film.

Wherein, in the step one, substrate includes：Silicon chip with silicon nitride film；Wherein, the thickness of silicon nitride film can be 200nm~500nm.

In the step one, etching technics includes：Plasma etch process；Wherein, the ginseng of plasma etch process Number is preferably as follows：

Etching uses argon gas for ion source gas, 1~10torr of pressure, 20~35 degrees Celsius of temperature, and power 100~ 500W, 5~20s of processing time, etch amount 5nm~20nm.

In the step 2, the method for film forming includes：Physical sputtering method；The pressure of film forming is preferably 1~10torr, into The temperature of film is preferably 20~35 degrees Celsius；The thickness of Ta films is preferably 100~500 angstroms；

Preferably, the method for film forming is the platform substrate bias of physical sputtering power (DC power) and carrying substrates (Bias) the alternately method of change, wherein, physical sputtering power changes from big to small, substrate bias changes (adopt from small to large Alternated with high sputtering power with low Bias voltages), as in step 2, substrate bias can be linearly increasing from 0.01~0.3kw, thing Reason sputtering power can successively decrease from 0.6~0.2kw.

It is highly preferred that entering row metal Ta film forming using the method comprised the following steps：

The first step, 400W~600W high power sputtering and the 10W~100W thickness of low-power substrate bias film forming 1/2；

Second step, 400W~500W low-power sputtering and the thickness of substrate bias film forming 1/4 of 100W~200W power；

3rd step, 300W~400W low-power sputtering and the 200W~300W thickness of high power substrate bias film forming 1/4.

In the step 3, on the Ta films surface, Ni is first carried out₈₁Fe₁₉The film forming of film, then, then carries out nitridation tantalum film Film forming.

In the step 3, Ni₈₁Fe₁₉The film build method of film includes：Physical sputtering method；Wherein, sputtering power is preferably 0.1kw~1kw, sputtering pressure is preferably 1 × 10^-8Support~1 × 10^-5Support.

In the step 3, the film build method of nitridation tantalum film includes：Physical sputtering method；Wherein, sputter temperature is preferably 20 DEG C~50 DEG C, sputtering pressure is preferably the support of 1 support~10, and sputtering power is preferably 0.5kw~2kw；The thickness for nitrogenizing tantalum film is excellent Elect 200~1000 angstroms as.

In the step 4, the temperature of annealing is preferably 400~600 DEG C, and processing time is preferably 30 seconds~60 seconds.

It is main to be complementary to one another using thin film sputtering power with substrate bias in the Ta film forming procedures of the present invention, prevent because splashing Penetrate the power secondary sputtering bigger than normal caused and increase the defect of film：High sputtering power is effectively increased bottom film consistency, from And trigger film to tend to growth (111) crystal face；Low-power sputtering effectively can prevent defect from increasing, can while increasing substrate bias Film crystallization degree is improved with the consistency for increasing sputtered film, in this way, being grown in the Ni of such Ta cushions₈₁Fe₁₉Film Amr effect it is also bigger.Therefore, the Ta cushions that film build method institute of the present invention film forming comes out, can be prevented effectively from high power and splash Film forming is bad caused by film crystal defect caused by penetrating and low-power sputtering.

Thus, in the present invention, cushion Ta can significantly improve Ni₈₁Fe₁₉The AMR values of film, and with Ta film work( Rate increase, Ni₈₁Fe₁₉The AMR values of film are improved therewith, and it is because the Ta cushions formed make film as power increases It is finer and close.Therefore, the present invention can be reduced effectively due to high power using the Ta cushions of variable-current mode film forming formation The crystal defect caused is sputtered, because crystal defect seriously causes Ni₈₁Fe₁₉Tending to growth, the buffering that the present invention is formed film more Layer Ta can effectively improve Ni₈₁Fe₁₉Film (111) crystal face tends to film forming, so as to effectively improve Ni₈₁Fe₁₉The AMR of film Effect.

Brief description of the drawings

The present invention is further detailed explanation with embodiment below in conjunction with the accompanying drawings：

When Fig. 1 is fixed substrate bias, physical sputtering power increases the Ta+Ni to be formed₈₁Fe₁₉The AMR values of film；

AMR design sketch when Fig. 2 is physical sputtering power (DC power) change, wherein, the implication of the 1-7 in Fig. 2 is shown in Table 1.It is pointed out that " step of the first step-the three " in table 1 refers to the film forming for entering row metal Ta using above-mentioned three-step approach, and And the power (W) in the substrate bias in 1-7 is changed from 100W-200W-300W.

Table 1

Embodiment

The metal Ta film build methods for improving magnetic film AMR of the present invention, including step：

(1) step one, using plasma etching technics is pre-processed to substrate, to increase the thick of the substrate surface Rugosity；

Wherein, substrate can be the silicon chip with silicon nitride film (thickness of silicon nitride film can be 200nm-500nm)；

The parameter of plasma etch process can be as follows：

(2) step 2, row metal Ta film forming is entered in the substrate surface, forms Ta films (Ta films can be used as cushion)；

Wherein, the pressure of film forming can be 1~10torr, and film-forming temperature can be 20~35 degrees Celsius；

The thickness of Ta films can be 100~500 angstroms；

The method of the film forming of Ta films includes：Physical sputtering method；Concretely：Physical sputtering power (DC power) is with holding The method that the platform substrate bias (Bias) of silicon chip alternately changes is carried, it is comprised the following steps that：

(3) step 3, on the Ta films surface, first carries out Ni₈₁Fe₁₉The film forming of film, then, then carries out nitrogenizing tantalum film Film forming.

Wherein, Ni₈₁Fe₁₉The film build method of film can be physical sputtering method, and sputtering power can be 0.1kw~1kw, sputtering Pressure can be 1 × 10^-8Support~1 × 10^-5Support.Ni₈₁Fe₁₉The thickness of film can be required according to common process.

Nitrogenize tantalum film film build method can physical sputtering method, sputter temperature can be 20 DEG C~50 DEG C, sputtering pressure can be 1 ~10 supports are held in the palm, sputtering power can be 0.5kw~2kw；

The thickness for nitrogenizing tantalum film can be 200~1000 angstroms.

(4) step 4, to the Ta films, Ni₈₁Fe₁₉Film and nitridation tantalum film carry out annealing 30 at 400~600 DEG C Second~60 seconds, so as to form anisotropic magnetoresistance film.

Operated according to above-mentioned steps, Ni can be effectively improved₈₁Fe₁₉The amr effect of film.

Wherein, when fixed substrate bias, physical sputtering power increases the Ta+Ni to be formed₈₁Fe₁₉The AMR values of film are as schemed Shown in 1.Meanwhile, it is maximum when fixed change substrate bias changes from 100w-200w-300w and X-axis is physical sputtering power film forming Value (power is X → X-100W → X-200W during film forming), the Ta+Ni of formation₈₁Fe₁₉The AMR values of film are as shown in Figure 2.In Fig. 2, Ni of the physical sputtering power from 600~100w Ta cushions changed₈₁Fe₁₉The amr effect of film is most strong.

Claims

1. a kind of metal Ta film build methods for improving magnetic film AMR, it is characterised in that including step：

Step one, substrate is handled using etching technics；

Step 2, row metal Ta film forming is entered in the substrate surface, forms Ta films；The method of film forming be physical sputtering power with The method that the platform substrate bias power of carrying substrates alternately changes, wherein, physical sputtering power changes from big to small, substrate is inclined Power is put from small to large to change；

Step 4, to the Ta films, Ni₈₁Fe₁₉Film and nitridation tantalum film are made annealing treatment, so as to form anisotropic magnetoresistance Film.

2. the method as described in claim 1, it is characterised in that：In the step one, substrate includes：Silicon substrate with silicon nitride film Piece；Wherein, the thickness of silicon nitride film is 200nm~500nm；

Etching technics includes：Plasma etch process.

3. method as claimed in claim 2, it is characterised in that：The parameter of the plasma etch process is as follows：

Etching uses argon gas for ion source gas, 1~10torr of pressure, 20~35 degrees Celsius of temperature, 100~500W of power, place 5~20s of reason time, etch amount 5nm~20nm.

4. the method as described in claim 1, it is characterised in that：In the step 2, the method for film forming includes：Physical sputtering side Method；

The pressure of film forming is 1~10torr, and the temperature of film forming is 20~35 degrees Celsius；

The thickness of Ta films is 100~500 angstroms.

5. the method as described in claim 1, it is characterised in that：The physical sputtering power successively decreases from 0.6~0.2kw, substrate Bias power is linearly increasing from 0.01~0.3kw.

6. the method as described in claim 1 or 5, it is characterised in that the method for the film forming, which is used, to be comprised the following steps Method enters row metal Ta film forming：

The first step, 400W~600W high power sputtering and the 10W~100W thickness of low-power substrate bias power film forming 1/2；

Second step, 400W~500W low-power sputtering and the thickness of substrate bias power film forming 1/4 of 100W~200W power；

3rd step, 300W~400W low-power sputtering and the 200W~300W thickness of high power substrate bias power film forming 1/4.

7. the method as described in claim 1, it is characterised in that：In the step 3, on the Ta films surface, first carry out Ni₈₁Fe₁₉The film forming of film, then, then nitrogenize the film forming of tantalum film；

Ni₈₁Fe₁₉The film build method of film includes：Physical sputtering method；Wherein, sputtering power is 0.1kw~1kw, and sputtering pressure is 1 ×10^-8Support~1 × 10^-5Support.

8. the method as described in claim 1, it is characterised in that：In the step 3, the film build method of nitridation tantalum film includes：Thing Manage sputtering method；Wherein, sputter temperature is 20 DEG C~50 DEG C, and sputtering pressure is the support of 1 support~10, sputtering power be 0.5kw~ 2kw；

The thickness for nitrogenizing tantalum film is 200~1000 angstroms.

9. the method as described in claim 1, it is characterised in that：In the step 4, the temperature of annealing is 400~600 DEG C, processing time is 30 seconds~60 seconds.